"My choreographer actually, when I was doing the rehearsals for this video, he was like, 'Britney, you are not a sweet mommy in this video. You are nasty bitch mommy in this video'," Spears told E!.

"And I was like, 'OK...' When you start to feel the character, you start to feel silly because you're like, 'This isn't me, I'm not like this'. Moving all sexually and stuff like that. As mommy you feel really awkward doing that."

The 31-year-old added that she even surprised herself after watching back the footage, revealing: "Once you get out there and the camera starts rolling, you just kind of feel it out.

"When I watch playbacks sometimes, I'm like, 'Who do I think I am?! Who the hell do I think I am?!'"

'Work Bitch' is out now everywhere except the UK, where it will be released on November 3. Her eighth studio album follows on December 3.

Spears has also announced a Las Vegas residency called 'Piece of Me', which starts at Planet Hollywood on December 27.